Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 39
Filtrar
1.
Zhonghua Zhong Liu Za Zhi ; 45(5): 415-423, 2023 May 23.
Artigo em Zh | MEDLINE | ID: mdl-37188627

RESUMO

Objective: To development the prognostic nomogram for malignant pleural mesothelioma (MPM). Methods: Two hundred and ten patients pathologically confirmed as MPM were enrolled in this retrospective study from 2007 to 2020 in the People's Hospital of Chuxiong Yi Autonomous Prefecture, the First and Third Affiliated Hospital of Kunming Medical University, and divided into training (n=112) and test (n=98) sets according to the admission time. The observation factors included demography, symptoms, history, clinical score and stage, blood cell and biochemistry, tumor markers, pathology and treatment. The Cox proportional risk model was used to analyze the prognostic factors of 112 patients in the training set. According to the results of multivariate Cox regression analysis, the prognostic prediction nomogram was established. C-Index and calibration curve were used to evaluate the model's discrimination and consistency in raining and test sets, respectively. Patients were stratified according to the median risk score of nomogram in the training set. Log rank test was performed to compare the survival differences between the high and low risk groups in the two sets. Results: The median overall survival (OS) of 210 MPM patients was 384 days (IQR=472 days), and the 6-month, 1-year, 2-year, and 3-year survival rates were 75.7%, 52.6%, 19.7%, and 13.0%, respectively. Cox multivariate regression analysis showed that residence (HR=2.127, 95% CI: 1.154-3.920), serum albumin (HR=1.583, 95% CI: 1.017-2.464), clinical stage (stage Ⅳ: HR=3.073, 95% CI: 1.366-6.910) and the chemotherapy (HR=0.476, 95% CI: 0.292-0.777) were independent prognostic factors for MPM patients. The C-index of the nomogram established based on the results of Cox multivariate regression analysis in the training and test sets were 0.662 and 0.613, respectively. Calibration curves for both the training and test sets showed moderate consistency between the predicted and actual survival probabilities of MPM patients at 6 months, 1 year, and 2 years. The low-risk group had better outcomes than the high-risk group in both training (P=0.001) and test (P=0.003) sets. Conclusion: The survival prediction nomogram established based on routine clinical indicators of MPM patients provides a reliable tool for prognostic prediction and risk stratification.


Assuntos
Mesotelioma Maligno , Humanos , Prognóstico , Nomogramas , Estudos Retrospectivos , Modelos de Riscos Proporcionais
2.
Artigo em Zh | MEDLINE | ID: mdl-33781035

RESUMO

Objective: To explore the relationship between the health literacy of employees and smoking, drinking, diet and exercise, and provide scientific basis for health education and targeted intervention. Methods: From February to July 2019, a cluster random sampling method was adopted to select enterprise employees in Shihezi City to conduct a questionnaire survey. Self-made questionnaires and "National Resident Health Literacy Monitoring Questionnaire" were used to assess the social demographics, health literacy, and Health-related behaviors were investigated, and 1053 valid questionnaires were collected. Logistic regression model was used to analyze the relationship between health literacy and the three dimensions with smoking, drinking, diet and exercise. Results: Total score of health literacy of enterprise employees is (42.06±11.03) points and the employee health literacy rate of Shihezi City in 2019 is 19.47%. Univariate analysis showed that non-smokers had higher health literacy and three-dimensional health literacy availability than smokers (P<0.01) ; fewer drinkers had higher health literacy availability than overdrinkers (P<0.05) ; balanced diet health literacy availability The health literacy availability rates in the three dimensions were higher than those in the unbalanced diet (P<0.01) . In the logistic regression analysis, healthy lifestyle and behavioral literacy were independently related to smoking behavior (OR=1.571, P<0.05) ; the presence of health literacy and the three dimensions of health literacy were not statistically related to alcohol consumption (P>0.05) ; there is a statistical correlation between health literacy, healthy lifestyles, behaviors, and health skills and regular exercise among employees (OR=1.829、2.503、1.395, P<0.05) ; employees with health literacy and three dimensions of health literacy are more likely to have a balanced diet (P<0.01) . Conclusion: There is a correlation between the health literacy of enterprise employees and diet and exercise. The improvement of health literacy level is an important way to interfere with unhealthy behaviors.


Assuntos
Letramento em Saúde , Consumo de Bebidas Alcoólicas/epidemiologia , Estudos Transversais , Exercício Físico , Comportamentos Relacionados com a Saúde , Inquéritos e Questionários
3.
Zhonghua Zhong Liu Za Zhi ; 40(6): 452-455, 2018 Jun 23.
Artigo em Zh | MEDLINE | ID: mdl-29936772

RESUMO

Objective: To investigate the clinicopathological characteristics, therapy and prognosis of patients with pulmonary mucoepidermoid carcinoma. Methods: The clinical data of 87 patients diagnosed as pulmonary mucoepidermoid carcinoma at The First Affiliated Hospital of Zhengzhou University from April 2011 to May 2016 were retrospectively analyzed. The clinicopathological features were summarized and the prognoses were analyzed. Results: Among the 87 patients with lung mucoepidermoid carcinoma, 53 were male and 34 were female, the gender ratio between men and women was 1.56∶1.The ages of patients were from 16 to 79 years and the median age was 52.5 years. Seventeen cases were diagnosed as stage Ⅰ, 28 cases were stage Ⅱ, 26 cases were stage Ⅲ, 16 cases were stage Ⅳ.Thirty-six patients were examined by immunohistochemistry, of which 29 cases were cytokeratin (CK) 5/6 positive, 29 cases were CK7 positive, 10 cases were CK positive, 28 cases were p63 positive, 14 cases were p40 positive, 17 cases were thyroid transcription factor-1 (TTF-1) positive, 11 cases were NapsinA positive, 2 cases were epithelial membrane antigen (EMA) positive, 4 cases were CK8/18 positive, 3 cases were surfactant proteins A (SPA) positive, 1 case was CAM5.2 positive and 1 case was CK14 positive. Among the 87 patients, 34 cases were treated by operation alone, 23 cases were treated by operation combined with chemotherapy, 5 cases were treated by radiotherapy combined with chemotherapy, 14 cases were treated by chemotherapy alone, 2 cases were treated by particle implantation combined with chemotherapy, 2 cases were treated by local radiofrequency hyperthermia combined with chemotherapy, and 7 cases without special treatment.Five patients with brain metastasis were treated with cerebral radiotherapy combined with sequential chemotherapy. The 1-year, 2-year and 5-year survival rates of 87 patients were 90.7%, 81.6% and 46.3%, respectively. The median survival time was 60 months. The prognoses of patients with lung mucoepidermoid carcinoma were related with the clinical stage, smoking and operative therapy (all P<0.05). Conclusions: The age distribution of patients with pulmonary mucoepidermoid is a wide range, the incidence of male is higher than that of female. The diagnosis of pulmonary mucoepidermoid carcinoma mainly relies on the morphological diagnosis and the immunohistochemical detection is non-specific. The prognoses of patients with lung mucoepidermoid carcinoma are related with clinical stage, smoking and operative therapy. For patients who are inoperable and with single distant metastasis, local radiotherapy, other local treatment and chemotherapy can significantly improve their prognoses.


Assuntos
Carcinoma Mucoepidermoide , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Adolescente , Adulto , Idoso , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/secundário , Carcinoma Mucoepidermoide/sangue , Carcinoma Mucoepidermoide/mortalidade , Carcinoma Mucoepidermoide/patologia , Carcinoma Mucoepidermoide/secundário , Carcinoma Pulmonar de Células não Pequenas/sangue , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Carcinoma Pulmonar de Células não Pequenas/patologia , Feminino , Humanos , Imuno-Histoquímica , Neoplasias Pulmonares/sangue , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/sangue , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida , Adulto Jovem
4.
Zhonghua Fu Chan Ke Za Zhi ; 53(3): 155-159, 2018 Mar 25.
Artigo em Zh | MEDLINE | ID: mdl-29609228

RESUMO

Objective: To explore the occurrence of fetal chromosomal abnormalities among pregnant women with an adverse reproductive history using traditional karyotyping and single nucleotide polymorphism microarray (SNP-array) technology. Methods: Totally 94 in 2 163 (4.35%) cases of singleton pregnant women with an adverse reproductive history were performed amniocentesis in Jinhua Maternal and Child Health Care Hospital from June 2015 to June 2017. Traditional karyotyping and SNP-array were employed simultaneously for prenatal diagnosis, and the detection rates of the two methods were compared. Results: All of the 94 specimens were successfully analyzed, 11 cases were found with chromosomal anomaly, the overall detection rate was 11.7%(11/94). Seven (7.4%,7/94) abnormalities cases were detected by karyotyping, and 7(7.4%) by SNP-array. The karyotyping results of trisomy 21, and 45,X and the deletion of chromosome 13 were consistent with SNP-array. Only 3 (3.2%, 3/94) microdeletion/duplications (the sizes of duplications and deletions were between 422.4-1 708.4 kb) and 1 (1/4) loss of heterozygosity were detected by SNP-array, but were missed by karyotyping. Furthermore, 2 cases' copy number variation were found pathogenic gene related, while the other 2 were considered benign or variant of uncertain significance. Four cases (4/7) of abnormalities were detected by karyotyping, while confirmed balanced translocation and inversion by SNP-array. All patients were informed and chosen to continue the pregnancy. Conclusions: The rate of abnormal fetal chromosomes in pregnant women with an adverse reproductive history is still high. SNP-array is a new molecular genetic technique, and combined with use of traditional karyotyping, it could improve the detection rate of fetal chromosomal abnormalities and reduce abortion rate, thus providing a basis for genetic counseling and prenatal diagnosis.


Assuntos
Amniocentese/métodos , Transtornos Cromossômicos/diagnóstico , Transtornos Cromossômicos/genética , Variações do Número de Cópias de DNA , Cariotipagem , Polimorfismo de Nucleotídeo Único , Complicações na Gravidez/genética , Diagnóstico Pré-Natal/métodos , Aberrações Cromossômicas , Cromossomos Humanos Par 13 , Síndrome de Down/diagnóstico , Síndrome de Down/genética , Feminino , Feto , Aconselhamento Genético , Humanos , Cariotipagem/métodos , Gravidez , Complicações na Gravidez/diagnóstico , História Reprodutiva , Trissomia
6.
J Periodontal Res ; 50(1): 89-102, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24862405

RESUMO

BACKGROUND AND OBJECTIVE: Periodontal disease is a highly complex chronic inflammatory disease of the oral cavity. Multiple factors influence periodontal disease, including socio-economic status, genetics and age; however, inflammation elicited by the presence of specific bacteria in the subgingival space is thought to drive the majority of soft- and hard-tissue destruction. Porphyromonas gingivalis is closely associated with periodontal disease. Toll-like receptors (TLRs) and their intracellular signaling pathways play roles in the host response to P. gingivalis. The focus of the current study was to use microarray analysis to define the contributions of the TLR adaptor molecules myeloid differentiation factor 88 (MyD88) and Toll/interleukin-1 receptor domain-containing adaptor inducing interferon-beta (TRIF), and aging, on the expression of TLR pathway-associated mRNAs in response to P. gingivalis. MATERIAL AND METHODS: Bone marrow-derived macrophages (BMØ) from wild-type (Wt), MyD88 knockout (MyD88-KO) and Trif(Lps2) [i.e. containing a point mutation in the lipopolysaccharide 2 (Lps2) gene rendering the Toll/interleukin (IL)-1 receptor domain-containing adaptor inducing interferon-beta (TRIF) protein nonfunctional] mice, at 2-and 12-mo of age, were cultured with P. gingivalis. Expression of genes in BMØ cultured with P. gingivalis was determined in comparison with expression of genes in BMØ cultured in medium only. RESULTS: Using, as criteria, a twofold increase or decrease in mRNA expression, differential expression of 32 genes was observed when Wt BMØ from 2-mo-old mice were cultured with P. gingivalis compared with the medium-only control. When compared with 2-mo-old Wt mice, 21 and 12 genes were differentially expressed (p < 0.05) as a result of the mutations in MyD88 or TRIF, respectively. The expression of five genes was significantly (p < 0.05) reduced in Wt BMØ from 12-mo-old mice compared with those from 2-mo-old mice following culture with P. gingivalis. Age also influenced the expression of genes in MyD88-KO and Trif(Lps2) mice challenged with P. gingivalis. CONCLUSIONS: Our results indicate that P. gingivalis induces differential expression of TLR pathway-associated genes, and both MyD88 and TRIF play roles in the expression of these genes. Age also played a role in the expression of TLR-associated genes following stimulation of BMØ with P. gingivalis.


Assuntos
Proteínas Adaptadoras de Transporte Vesicular/genética , Envelhecimento/genética , Fator 88 de Diferenciação Mieloide/genética , Porphyromonas gingivalis/imunologia , Transdução de Sinais/genética , Receptores Toll-Like/genética , Envelhecimento/imunologia , Animais , Células da Medula Óssea/imunologia , Células Cultivadas , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/genética , Técnicas de Inativação de Genes , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Lipopolissacarídeos/genética , Macrófagos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Análise em Microsséries , Mutação Puntual/genética
7.
J Cell Biol ; 101(2): 420-6, 1985 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-2410431

RESUMO

Fertilization of the sea urchin egg triggers a sequence of events that are necessary for metabolic derepression and stimulation of proliferation. Changes in intracellular Ca2+ and H+ activities regulate the sequence of events. Intracellular sodium activity is important in the regulation of the intracellular activities of these ions and may directly regulate metabolic events. Using Na+-sensitive microelectrodes we continuously measured the intracellular Na+ activity during fertilization. The results show an increase in intracellular sodium activity medicated by two pathways of Na+ entry: Na+ permeability increase during the fertilization potential and initiation of Na+-H+ exchange activity. Intracellular Na+ activity returned to unfertilized levels by 20 min after fertilization. This decrease was inhibited by ouabain, which suggests the activation of Na+, K+ ATPase during fertilization.


Assuntos
Fertilização , Canais Iônicos/metabolismo , Óvulo/metabolismo , Ouriços-do-Mar/metabolismo , Sódio/metabolismo , Amilorida/farmacologia , Animais , Feminino , Fertilização/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Líquido Intracelular/metabolismo , Ouabaína/farmacologia , Óvulo/fisiologia , Água do Mar
8.
Curr Opin Genet Dev ; 2(4): 642-6, 1992 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1525519

RESUMO

Calcium is well established as a second messenger in a diverse array of cell activities. Changes in intracellular Ca2+ activities range from localized releases to complex oscillations, which may encode specific cellular signals. The full variety of calcium responses is observed during the fertilization of different animal oocytes and eggs. Current research has focused on the cellular mechanisms that generate these Ca(2+)-activity changes.


Assuntos
Cálcio/fisiologia , Fertilização/fisiologia , Óvulo/metabolismo , Transdução de Sinais/fisiologia , Animais , Cálcio/metabolismo
9.
R Soc Open Sci ; 5(5): 171979, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29892385

RESUMO

A hollow fibre membrane was fabricated by blending polyvinylidene fluoride (PVDF) with a triblock copolymer additive polymer that has both hydrophilic and oleophobic surface properties. The novel membrane was characterized and examined for oil/water separation under various system conditions, including different cross-flow rate, feed temperature, trans-membrane pressure, and its rejection and cleaning efficiency, etc. By applying the membrane into the filtration of synthesized oil/water emulsion, the membrane constantly achieved an oil rejection rate of above 99%, with a relatively constant permeate flux varied in the range of 68.9-59.0 l m-2 h-1. More importantly, the fouling of the used membrane can be easily removed by simple water flushing. The membrane also demonstrated a wide adaptability for different types of real oily wastewater, even at very high feed oil concentration (approx. 115 000 mg l-1 in terms of chemical oxygen demand (COM)). Hence, the novel triblock copolymer additive-modified PVDF membrane can have a great prospect in the continuing effort to expand the engineering application of polymeric membranes for oily wastewater treatment.

10.
Cancer Res ; 38(5): 1356-61, 1978 May.
Artigo em Inglês | MEDLINE | ID: mdl-205364

RESUMO

Using electrophysiological techniques we have examined the apical membrane ionic permeabilities of primary cell cultures of the mouse mammary gland in the midpregnant, preneoplastic, and neoplastic states. Membrane Na+ permeability changed with tumorigenesis, whereas K+ and Cl- permeabilities were unaltered. With tracer flux techniques the unidirectional efflux rate constant of 22Na was found to be greater in tumor cells than it is in normal cells. This increase in 22Na efflux was eliminated by the addition of ouabain. The results are interpreted as an increase in Na+ permeability and in Na+-K+-ATPase activity with the neoplastic transformation. The presence or absence of the virus in midpregnant cells does not seem to affect Na+ permeability.


Assuntos
Neoplasias Mamárias Experimentais/fisiopatologia , Lesões Pré-Cancerosas/fisiopatologia , Sódio/fisiologia , Animais , Permeabilidade da Membrana Celular , Células Cultivadas , Cloretos/fisiologia , Feminino , Glândulas Mamárias Animais/fisiologia , Vírus do Tumor Mamário do Camundongo , Potenciais da Membrana , Camundongos , Concentração Osmolar , Potássio/fisiologia , Gravidez , Infecções Tumorais por Vírus/fisiopatologia
12.
Biochem Biophys Res Commun ; 161(3): 1100-8, 1989 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-2545196

RESUMO

Fertilization of the sea urchin egg initiates or accelerates a number of metabolic activities, which have been causally linked to a rise in cytoplasmic pH due to increased Na+-H+ antiport. Two possible regulatory pathways linking sperm-egg fusion to the activity of the antiporter are activation of protein kinase C (PKC) and Ca2+, calmodulin (CaM)-dependent kinase. This report presents the effects of protein kinase inhibitors on antiporter activation during fertilization and treatment with PKC agonists, dioctanoylglycerol or phorbol diester. Protein kinase inhibitors, K252a and H-7 blocked the action of PKC agonists, without inhibiting cytoplasmic alkalinization during fertilization. In contrast, W-7 blocked fertilization-induced rise in cytoplasmic pH, without altering the actions of PKC agonists. These results suggest that the Na+-H+ antiporter may be regulated by PKC or Ca2+, CaM-dependent kinase activities, but activation of the antiporter during fertilization is Ca2+, CaM-dependent, despite production of diacylglycerols by hydrolysis of phosphatidylinositols.


Assuntos
Carbazóis/farmacologia , Proteínas de Transporte/metabolismo , Fertilização , Isoquinolinas/farmacologia , Óvulo/metabolismo , Piperazinas/farmacologia , Proteína Quinase C/antagonistas & inibidores , Sulfonamidas/farmacologia , 1-(5-Isoquinolinasulfonil)-2-Metilpiperazina , Animais , Bloqueadores dos Canais de Cálcio/farmacologia , Proteínas de Transporte/antagonistas & inibidores , Feminino , Alcaloides Indólicos , Cinética , Óvulo/efeitos dos fármacos , Ouriços-do-Mar , Trocadores de Sódio-Hidrogênio , Acetato de Tetradecanoilforbol/farmacologia
13.
Proc Natl Acad Sci U S A ; 81(5): 1436-9, 1984 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-6584890

RESUMO

The electrical block to fertilization of sea urchin eggs can be overcome by very brief periods of inside-negative egg membrane potential. Lytechinus pictus eggs whose membrane potentials have been clamped at +15 mV cannot be fertilized. If the membrane potential is repolarized to inside-negative voltages for a brief interval, the egg can be successfully fertilized. By varying the duration and voltage of these brief periods of inside negativity, we have uncovered three general properties of the electrically sensitive step in fertilization. First, a membrane-potential step that becomes rate limiting at inside-positive voltages can be initiated within a few milliseconds of inside negativity (30-60 msec at -60 mV). Second, at the time that the electrically sensitive step is being completed, there are other potential-independent steps with probably slower time constants because the duration of negativity was more effective applied as paired pulses rather than a single long pulse. Third, the permissive state is more quickly established by inside negativity than the nonpermissive state is established by inside positivity because the interval between paired pulses could be a few times longer than the effective single pulse in duration. In these voltage-clamped eggs the intervals from the successful completion of the electrically sensitive step to the next identifiable signs of activation were on the order of several seconds and highly variable.


Assuntos
Fertilização , Óvulo/fisiologia , Interações Espermatozoide-Óvulo , Espermatozoides/fisiologia , Animais , Condutividade Elétrica , Feminino , Masculino , Potenciais da Membrana , Ouriços-do-Mar , Fatores de Tempo
14.
Exp Cell Res ; 183(2): 343-52, 1989 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-2548885

RESUMO

Fertilization of the sea urchin egg is accompanied by changes in intracellular ion activities and transmembrane fluxes, which regulate the sequence of biochemical events of metabolic derepression. Changes in intracellular K+ activity during fertilization have been controversial and here we report our measurements using intracellular K+-sensitive microelectrodes. A small, but statistically significant, transient rise in internal K+ activity was detected during the first 10 min of fertilization. Since this change in K+ activity was ouabain sensitive, intracellular K+ activity in the fertilized egg appears to be regulated by the increased Na+, K+ ATPase activity, rather than the previously suggested K+ decompartmentalization. Increasing external K+ concentration was found to stimulate ouabain-sensitive alkalinization in the fertilized egg. The data are consistent with the possibility that Na+, K+ ATPase may regulate cytoplasmic pH by recycling Na+ that enters the cell through Na+-H+ antiport.


Assuntos
Fertilização , Óvulo/fisiologia , Potássio/fisiologia , Animais , Proteínas de Transporte/metabolismo , Eletrofisiologia/métodos , Feminino , Homeostase , Concentração de Íons de Hidrogênio , Potenciais da Membrana , Microeletrodos , Ouabaína/farmacologia , Óvulo/efeitos dos fármacos , Ouriços-do-Mar , Trocadores de Sódio-Hidrogênio
15.
Dev Biol ; 225(1): 253-64, 2000 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-10964479

RESUMO

Protein tyrosine kinase activity has been implicated as part of the signaling mechanism leading to the sperm-induced calcium transient following fertilization. In the present study, we have tested the role of the Fyn kinase in triggering the calcium transient by microinjecting domain-specific fusion proteins encoding regions of Fyn sequence as inhibitors of Fyn function in vivo. A fusion protein encoding the SH2 domain of Fyn caused an increase in the latent period between sperm-egg fusion and the beginning of the calcium transient and reduced the amplitude of the calcium signal. A fusion protein encoding the U + SH3 domains also caused a small increase in the latent period. Microscopic examination revealed that a large percentage of eggs injected with the U+SH3 or SH2 domains became polyspermic as a result of the delayed block to polyspermy. Affinity experiments demonstrated that the U+SH3 and SH2 domains of Fyn were capable of forming a stable complex with phospholipase Cgamma from the sea urchin egg. The results suggest that the Fyn kinase participates in the signaling events leading up to the calcium transient and may directly regulate phospholipase Cgamma activity at fertilization.


Assuntos
Cálcio/fisiologia , Proteínas Proto-Oncogênicas/fisiologia , Ouriços-do-Mar/embriologia , Ouriços-do-Mar/fisiologia , Interações Espermatozoide-Óvulo/fisiologia , Animais , Feminino , Masculino , Proteínas Tirosina Quinases/fisiologia , Proteínas Proto-Oncogênicas c-fyn , Transdução de Sinais
16.
Biol Reprod ; 62(4): 873-8, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10727255

RESUMO

Fertilization-induced Ca(2+) oscillations in mouse eggs cease at the time of pronuclear formation when maturation-promoting factor (MPF) is inactivated, but the Ca(2+) oscillations are ceaseless if eggs are arrested at metaphase by colcemid, which maintains the activity of MPF. To determine the possible role of MPF in regulation of cytoplasmic Ca(2+) excitability, roscovitine, a specific inhibitor of p34(cdc2)/cyclin B kinase, was used to inactivate MPF, and its effect on fertilization-induced Ca(2+) oscillations was investigated. Our results showed that roscovitine at >/= 50 microM suppressed fertilization-induced Ca(2+) oscillations in normal and colcemid-treated metaphase II (MII) eggs after the first 1-2 Ca(2+) spikes. Roscovitine inhibition of fertilization-induced Ca(2+) oscillations could be reversed by extensive washing of the eggs. Histone H1 kinase activity in colcemid-treated MII eggs was similarly inhibited by roscovitine, which suggested that the cessation of fertilization-induced Ca(2+) oscillations is due to the inactivation of MPF. Thimerosal-induced Ca(2+) oscillations in Ca(2+)-, Mg(2+)-free medium was also suppressed by roscovitine, suggesting a general inhibitory effect of roscovitine on Ca(2+) oscillations. The inhibition may be achieved by disruption of Ca(2+) release and refilling of the calcium store. Thapsigargin, an inhibitor of the endoplasmic reticulum Ca-ATPase, induced significantly less Ca(2+) release in roscovitine-treated eggs than in the non-drug-treated eggs. Taken together, our results suggest that MPF plays an important role in regulation of the cytoplasmic Ca(2+) excitability in mouse eggs.


Assuntos
Proteína Quinase CDC2/antagonistas & inibidores , Sinalização do Cálcio/efeitos dos fármacos , Ciclina B/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Fertilização in vitro , Óvulo/efeitos dos fármacos , Proteínas Quinases , Purinas/farmacologia , Animais , Cálcio/química , Cálcio/metabolismo , ATPases Transportadoras de Cálcio/antagonistas & inibidores , Demecolcina/farmacologia , Feminino , Técnicas In Vitro , Masculino , Fator Promotor de Maturação/antagonistas & inibidores , Mesotelina , Camundongos , Camundongos Endogâmicos C57BL , Oócitos/efeitos dos fármacos , Inibidores de Proteínas Quinases , Roscovitina , Tapsigargina/farmacologia , Timerosal/farmacologia
17.
Dev Biol ; 193(2): 195-208, 1998 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-9473324

RESUMO

The production of inositol 1,4,5-trisphosphate (InsP3) has been reported to mediate the transient rise in intracellular Ca2+ activity ([Ca2+]i) in sea urchin eggs during fertilization. However, direct evidence of an absolute requirement for generation of InsP3 during fertilization is still lacking. We investigated this question by blocking the InsP3 synthesizing enzyme phospholipase C (PLC) during fertilization with U73122, an aminosteroid. U73122 inhibited the sperm-induced Ca2+ release in a dose-dependent manner, although above 15 microM U73122 eggs showed an elevated resting [Ca2+]i and a lower fertilization rate. The inhibition of Ca2+ transient by U73122 was not due to a failure of fertilization, since incorporated sperm nuclei were evident in eggs used to measure the Ca2+ response. U73122 also prevented the accompanying rise in intracellular pH (pHi), which is mediated by the activation of the Na+-H+ antiporter. The antiporter is regulated through activation of protein kinase C by 1,2-diacylglycerol, which is the other hydrolytic product of phosphatidylinositol 4,5-bisphosphate by PLC. Further evidence of the specificity of U73122 action was inhibition of the increase in InsP3 mass during the first 2 min of fertilization. In addition, U73122 inhibited the GTPgammaS-induced Ca2+ release and pHi rise in unfertilized eggs. These results suggested that the transient rise in Ca2+ in sea urchin during fertilization requires the production of InsP3.


Assuntos
Cálcio/fisiologia , Fertilização/fisiologia , Inositol 1,4,5-Trifosfato/biossíntese , Óvulo/fisiologia , Animais , Cálcio/antagonistas & inibidores , Cálcio/metabolismo , Citoplasma/efeitos dos fármacos , Citoplasma/metabolismo , Estrenos/farmacologia , Feminino , Fertilização/efeitos dos fármacos , Guanosina 5'-O-(3-Tiotrifosfato)/antagonistas & inibidores , Guanosina 5'-O-(3-Tiotrifosfato)/fisiologia , Concentração de Íons de Hidrogênio/efeitos dos fármacos , Inositol 1,4,5-Trifosfato/antagonistas & inibidores , Inositol 1,4,5-Trifosfato/fisiologia , Masculino , Óvulo/efeitos dos fármacos , Pirrolidinonas/farmacologia , Ouriços-do-Mar , Interações Espermatozoide-Óvulo/efeitos dos fármacos , Espermatozoides/efeitos dos fármacos , Espermatozoides/fisiologia
18.
Nature ; 282(5734): 87-9, 1979 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-41185

RESUMO

Several lines of evidence suggest that ionic messengers are primary agents in the metabolic derepression which occurs at fertilisation. The derepression at fertilisation or parthenogenetic activation of the sea urchin egg occurs in two main phases. The first phase, which triggers the early events of fertilisation, is mediated by transitory increase of intracellular free calcium. The second, which triggers the late events of fertilisation, is mediated by a rise in the intracellular pH (refs 4-6). The transition from the early events of fertilisation of sea urchin eggs to the late events requires a minimal concentration of sodium in the external medium. External Na+ is required for the acid effux which follows fertilisation. Na+ requirement and the acid effux have been correlated in a hypothesis which proposes that internal protons are exchanged for external Na+ (refs 8, 9). By using pH-sensitive microelectrodes, we have examined the relationship between external Na+ and internal pH more closely. We demonstrate here that the increase of the intracellular pH following egg activation does require external Na+. However, the relative insensitivity of the alkalisation of the egg cytoplasm to large reductions of external Na+ is evidence against the Na-H exchange hypothesis.


Assuntos
Fertilização , Concentração de Íons de Hidrogênio , Ouriços-do-Mar/fisiologia , Sódio/fisiologia , Regulação Alostérica , Amilorida/farmacologia , Animais , Calcimicina/farmacologia , Fertilização/efeitos dos fármacos , Potenciais da Membrana/efeitos dos fármacos
19.
Proc Natl Acad Sci U S A ; 87(23): 9285-9, 1990 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2251272

RESUMO

Fertilization initiates a transient increase in intracellular Ca2+ principally by Ca2+ release from intracellular stores. Possible multiple Ca2+ stores and multiple receptor regulation of the same store have been reported. Here we report the presence of at least two independent intracellular Ca2+ stores in the sea urchin egg, which are released during fertilization. Ca2+ release from one store is mediated by inositol 1,4,5-trisphosphate (IP3) and is sensitive to low molecular weight heparin. The other store is heparin insensitive and independent of IP3 regulation, but the regulatory factor remains unidentified. A transient increase in Ca2+ in heparin-loaded eggs is observed during fertilization, which suggests that IP3-independent Ca2+ release mediates the production of IP3 and release of the IP3-dependent store. Experiments presented here do not support the idea of sperm receptor coupling to inositol phospholipid hydrolysis through a GTP-binding protein mediating the fertilization response.


Assuntos
Cálcio/metabolismo , Fertilização , Óvulo/fisiologia , Animais , Feminino , Guanosina 5'-O-(3-Tiotrifosfato)/farmacologia , Heparina/farmacologia , Inositol 1,4,5-Trifosfato/farmacologia , Cinética , Masculino , Óvulo/efeitos dos fármacos , Ouriços-do-Mar , Espermatozoides/fisiologia
20.
Dev Biol ; 140(2): 272-80, 1990 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-2373253

RESUMO

Multiple second messenger pathways have been proposed for transduction of the sperm-egg fusion event during fertilization of sea urchin eggs. Cytoplasmic alkalinization due to increased Na(+)-H+ antiport has been causally linked to many of the metabolic events during fertilization. Two possible second messenger pathways coupling sperm-egg fusion and antiporter activity are activation of protein kinase C (PKC) and Ca2(+)-calmodulin kinase. A selective inhibitor of PKC is PKC(19-36), a synthetic peptide of the pseudosubstrate domain of the kinase. Injection of PKC(19-36) into unfertilized sea urchin eggs blocked cytoplasmic alkalinization during activation by phorbol 12-myristate 13-acetate, a PKC agonist. The rise in pH during fertilization was partially blocked by PKC(19-36), which suggested that multiple pathways regulate the antiporter during fertilization. The use of fluorescein chromophores to measure intracellular pH in sea urchin eggs is also discussed.


Assuntos
Fertilização , Óvulo/fisiologia , Peptídeos/farmacologia , Inibidores de Proteases , Proteína Quinase C/antagonistas & inibidores , Animais , Feminino , Fertilização/efeitos dos fármacos , Fluoresceínas , Corantes Fluorescentes , Concentração de Íons de Hidrogênio , Masculino , Óvulo/efeitos dos fármacos , Ouriços-do-Mar , Espectrometria de Fluorescência , Acetato de Tetradecanoilforbol/farmacologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA